Spiders and ants inspire a metallic structure that refuses to sink

November 06, 2019

University of Rochester researchers, inspired by diving bell spiders and rafts of fire ants, have created a metallic structure that is so water repellant, it refuses to sink - no matter how often it is forced into water or how much it is damaged or punctured.

Could this lead to:All of the above, says Chunlei Guo, professor of optics and physics, whose lab describes the structure in ACS Applied Materials and Interfaces.

The structure uses a groundbreaking technique the lab developed for using femtosecond bursts of lasers to "etch" the surfaces of metals with intricate micro- and nanoscale patterns that trap air and make the surfaces super-hydrophobic (water repellent).

The researchers found, however, that after being immersed in water for long periods of time, the surfaces may start to lose their hydrophobic properties.

Enter the spiders and fire ants, which can survive long periods under or on the surface of water. How? By trapping air in an enclosed area. Argyroneta aquatic spiders, for example, create an underwater dome-shaped web - a so-called diving bell - that they fill with air carried from the surface between their super-hydrophobic legs and abdomens. Similarly, fire ants can form a raft by trapping air among their superhydrophobic bodies.

"That was a very interesting inspiration," Guo says. As the researchers note in the paper: "The key insight is that multifaceted superhydrophobic (SH) surfaces can trap a large air volume, which points towards the possibility of using SH surfaces to create buoyant devices."

Guo's lab created a structure in which the treated surfaces on two parallel aluminum plates face inward, not outward, so they are enclosed and free from external wear and abrasion. The surfaces are separated by just the right distance to trap and hold enough air to keep the structure floating- in essence creating a waterproof compartment.

Even after being forced to submerge for two months, the structures immediately bounced back to the surface after the load was released, Guo says. The structures also retained this ability even after being punctured multiple times, because air remains trapped in remaining parts of the compartment or adjoining structures.

Though the team used aluminum for this project, the "etching process "could be used for literally any metals, or other materials," Guo says.

When the Guo lab first demonstrated the etching technique, it took an hour to pattern a one-inch-by-one-inch area of surface. Now, by using lasers seven times as powerful, and faster scanning, the lab has speeded up the process, making it more feasible for scaling up for commercial applications.
-end-
Coauthors include lead author Zhibing Zhan, Mohamed ElKabbash, Jihua Zhang, and Subhash Singh, all PhD candidates or postdoctoral fellows in Guo's lab, and Jinluo Cheng, associate professor at the Changchun Institute of Optics, Fine Mechanics, and Physics in China.

The project was supported by funding from the Bill & Melinda Gates Foundation, the US Army Research Office, and National Science Foundation.

University of Rochester

Related Spiders Articles from Brightsurf:

Environmental factors affect the distribution of Iberian spiders
Southern small-leaved oak forests are the habitats with a higher level of spider endemism in the Iberian Peninsula, according to an article published in the journal Biodiversity and Conservation.

These spiders can hear
Ogre-faced spiders hide during the day and hunt by night, dangling from palm fronds and casting nets on insects.

Untangling the social lives of spiders
Scientists begin to unravel the genetic mechanism by which a solitary spider becomes a social one.

Freshwater insects recover while spiders decline in UK
Many insects, mosses and lichens in the UK are bucking the trend of biodiversity loss, according to a comprehensive analysis of over 5,000 species led by UCL and the UK Centre for Ecology & Hydrology (UKCEH), and published in Nature Ecology & Evolution.

Cave fights for food: Voracious spiders vs. assassin bugs
Killing and eating of potential competitors has rarely been documented in the zoological literature, even though this type of interaction can affect population dynamics.

Spiders and ants inspire a metallic structure that refuses to sink
University of Rochester researchers have created a metallic structure that is so hydrophobic, it refuses to sink - no matter how often it is forced into water or how much it is damaged or punctured.

Compact depth sensor inspired by spiders
Inspired by jumping spiders, researchers at the Harvard John A.

Researchers find hurricanes drive the evolution of more aggressive spiders
Researchers at McMaster University who rush in after storms to study the behavior of spiders have found that extreme weather events such as tropical cyclones may have an evolutionary impact on populations living in storm-prone regions, where aggressive spiders have the best odds of survival.

Baby spiders really are watching you
Baby jumping spiders can hunt prey just like their parents do because they have vision nearly as good.

Solitude breeds aggression in spiders (rather than vice versa)
Spiders start out social but later turn aggressive after dispersing and becoming solitary, according to a study publishing July 2 in the open-access journal PLOS Biology by Raphael Jeanson of the National Centre for Scientific Research (CNRS) in France, and colleagues.

Read More: Spiders News and Spiders Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.